On Thu, Jun 7, 2018 at 7:42 AM Yu-cheng Yu <yu-cheng.yu@xxxxxxxxx> wrote:
>
> Add PTRACE interface for CET MSRs.
>
> Signed-off-by: Yu-cheng Yu <yu-cheng.yu@xxxxxxxxx>
> ---
> arch/x86/include/asm/fpu/regset.h | 7 ++++---
> arch/x86/kernel/fpu/regset.c | 41 +++++++++++++++++++++++++++++++++++++++
> arch/x86/kernel/ptrace.c | 16 +++++++++++++++
> include/uapi/linux/elf.h | 1 +
> 4 files changed, 62 insertions(+), 3 deletions(-)
>
> diff --git a/arch/x86/include/asm/fpu/regset.h b/arch/x86/include/asm/fpu/regset.h
> index d5bdffb9d27f..edad0d889084 100644
> --- a/arch/x86/include/asm/fpu/regset.h
> +++ b/arch/x86/include/asm/fpu/regset.h
> @@ -7,11 +7,12 @@
>
> #include <linux/regset.h>
>
> -extern user_regset_active_fn regset_fpregs_active, regset_xregset_fpregs_active;
> +extern user_regset_active_fn regset_fpregs_active, regset_xregset_fpregs_active,
> + cetregs_active;
> extern user_regset_get_fn fpregs_get, xfpregs_get, fpregs_soft_get,
> - xstateregs_get;
> + xstateregs_get, cetregs_get;
> extern user_regset_set_fn fpregs_set, xfpregs_set, fpregs_soft_set,
> - xstateregs_set;
> + xstateregs_set, cetregs_set;
>
> /*
> * xstateregs_active == regset_fpregs_active. Please refer to the comment
> diff --git a/arch/x86/kernel/fpu/regset.c b/arch/x86/kernel/fpu/regset.c
> index bc02f5144b95..7008eb084d36 100644
> --- a/arch/x86/kernel/fpu/regset.c
> +++ b/arch/x86/kernel/fpu/regset.c
> @@ -160,6 +160,47 @@ int xstateregs_set(struct task_struct *target, const struct user_regset *regset,
> return ret;
> }
>
> +int cetregs_active(struct task_struct *target, const struct user_regset *regset)
> +{
> +#ifdef CONFIG_X86_INTEL_CET
> + if (target->thread.cet.shstk_enabled || target->thread.cet.ibt_enabled)
> + return regset->n;
> +#endif
> + return 0;
> +}
> +
> +int cetregs_get(struct task_struct *target, const struct user_regset *regset,
> + unsigned int pos, unsigned int count,
> + void *kbuf, void __user *ubuf)
> +{
> + struct fpu *fpu = &target->thread.fpu;
> + struct cet_user_state *cetregs;
> +
> + if (!boot_cpu_has(X86_FEATURE_SHSTK))
> + return -ENODEV;
This whole series has a boot_cpu_has, static_cpu_has, and
cpu_feature_enabled all over. Please settle on just one, preferably
static_cpu_has.
> +
> + cetregs = get_xsave_addr(&fpu->state.xsave, XFEATURE_MASK_SHSTK_USER);
> +
> + fpu__prepare_read(fpu);
> + return user_regset_copyout(&pos, &count, &kbuf, &ubuf, cetregs, 0, -1);
> +}
> +
> +int cetregs_set(struct task_struct *target, const struct user_regset *regset,
> + unsigned int pos, unsigned int count,
> + const void *kbuf, const void __user *ubuf)
> +{
> + struct fpu *fpu = &target->thread.fpu;
> + struct cet_user_state *cetregs;
> +
> + if (!boot_cpu_has(X86_FEATURE_SHSTK))
> + return -ENODEV;
> +
> + cetregs = get_xsave_addr(&fpu->state.xsave, XFEATURE_MASK_SHSTK_USER);
> +
> + fpu__prepare_write(fpu);
> + return user_regset_copyin(&pos, &count, &kbuf, &ubuf, cetregs, 0, -1);
Is this called for core dumping on current? If so, please make sure
it's correct. (I think it is for get but maybe not for set.)
